1. Field of the Invention
This application claims priority to prior application JP 2003-342750, the disclosure of which is incorporated herein by reference
The present invention relates to an auto-negotiation monitor system, a repeating-transmission apparatus, and an auto-negotiation monitor method used therefor, and particularly relates to a technology for detecting a failure that occurs in a network for transferring an LAN (local area network) signal between switches via the repeating-transmission apparatus and determining the failure point.
2. Description of the Related Art
Usually, in a known network including Ethernet (a registered trademark) switches (hereinafter referred to as LAN switches) connected to each other with a long distance therebetween, a repeating-transmission apparatus is provided between the LAN switches for increasing the LAN-signal propagation distance (refer to Japanese Unexamined Patent Publication (JP-A) No. 2003-110585, for example).
In general, the repeating-transmission apparatus and the LAN switches are monitored by a monitor apparatus, so as to detect a failure and determine the failure point in the event of failure. However, where a failure occurs in an optical fiber on the reception side of the LAN switch, the failure can be detected only by the LAN switch, not by the repeating-transmission apparatus. That is to say, where a failure occurs in an optical fiber on the transmission side of the repeating-transmission apparatus, signal deterioration or optical-signal shutoff in the optical fiber can be detected only by the LAN switch. Though the repeating-transmission apparatus cannot monitor the signal deterioration, the optical-signal shutoff, and the link state of the LAN switches, this configuration presents no problem, as long as the monitor apparatus monitors the LAN switches and the repeating-transmission apparatus.
However, a problem may arise in the case where the LAN switches are not monitored by the monitor apparatus for some reason that the administrator or the monitor system for the LAN switches is different from that of the repeating-transmission apparatus. Where the administrator of the LAN switches is different from that of the repeating-transmission apparatus, the repeating-transmission apparatus is owned by a carrier for leasing lines and the LAN switch is owned by a customer of the carrier, for example. According to the above-described configuration, the monitor apparatus cannot monitor the LAN switch. Subsequently, the monitor apparatus cannot detect the failure in the reception-side optical fiber of the LAN switch and determine the failure point. Therefore, where a failure occurs in the reception-side optical fiber of the LAN switch, it takes much time to detect the failure, determine the failure point, and put the system back in order.